sphinxdocs .serve does not work when --symlink_prefix is set

[schenker]

🐞 bug report

Affected Rule

rules_python/sphinxdocs/private/sphinx.bzl

Lines 187 to 196 in 7c6b109

	py_binary(
	name = name + ".serve",
	srcs = [_SPHINX_SERVE_MAIN_SRC],
	main = _SPHINX_SERVE_MAIN_SRC,
	data = [html_name],
	args = [
	"$(execpath {})".format(html_name),
	],
	**common_kwargs_with_manual_tag
	)

Description

When using sphinx_docs to define my_docs, running bazel run //my_docs.serve outputs

Serving directory: /home/me/.../my-project/bazel-out/k8-dbg/bin/my_docs/_build/html

This works, until I use a different symlink prefix (https://bazel.build/reference/command-line-reference#build-flag--symlink_prefix). With a different symlink prefix, the served directory bazel-out does not exist which leads to a 404 error.

🌍 Your Environment

Operating System:

  
      Ubuntu 24.04.3 LTS
  

Output of bazel version:

  
    bazel 8.4.2
  

Rules_python version:

  
    1.6.3
  

[laurenshobert]

This issue appears to be related to bazelbuild/bazel#14821 (comment), which indicates a difference between the execroot and workspace directory layouts when Bazel’s --symlink_prefix flag is used.

I created a PR with a possible solution.